print(9//4)    #//为去整运算符
print(-9//-4)



print(9//-4)
print(-9//4)

print(9%-4)      #余数=被除数-除数*商   9-（-4）*（-3
print(-9%4)


print(9-4)
print(9/4)
print(9*4)
print(9+4)